1. Field of the Invention
This invention relates to an improved combustion turbine cycle which employs a combustion-gas expander and a compressor driven by that expander and in which excess fluid generated by a multi-stage, countercurrent humidifier is used to drive a turbine and/or is used as thermal diluent in a combuster for an additional combustion-gas expander.
2. State of the Art
The simplest form of combustion-turbine cycle includes three necessary components: (a) the combustion-gas expander, (b) a multi-stage compressor which compresses air or an oxygen-containing gas to a predetermined pressure and (c) a combustion chamber where the fuel and the air or other oxygen-containing gas react under pressure to produce a hot, pressurized gas stream which becomes the working fluid. The working fluid in turn energizes the expander. Such a cycle is generally known as a "simple cycle", or "Brayton cycle", and typically has a thermal efficiency of approximately 25% when the hot gas entering this expander is at a temperature of about 1800.degree. F.
The efficiency of any combustion turbine cycle is heavily, although not exclusively, influenced by three factors: